The cops may be letting him slip to get info on anyone who is helping him. IIRC when they got Eric Rudolph (Olympic Park bomber) they also indicted a number of other people.
If that’s teh case then they are keeping a close but not too close eye on him.
If that's the case, I'm guessing that he's being observed 24/7 by drones with cameras with high optic and thermal capabilities. Hiding from a large number of people in the field is probably a lot easier than hiding from an unseen eye in the sky with the ability to see in the dark.